/// <summary>
/// Gets a new specification expression which corresponds to the logical
/// combination of the specified objects: <c>AND</c>.
/// </summary>
/// <returns>A specification expression.</returns>
/// <param name="spec">A specification expression.</param>
/// <param name="composeWith">Another specification expression.</param>
/// <typeparam name="T">The generic type of the specifications.</typeparam>
public static ISpecificationExpression <T> And <T>(this ISpecificationExpression <T> spec, ISpecificationExpression <T> composeWith)
{
var func1 = spec.GetExpressionOrThrow();
var func2 = composeWith.GetExpressionOrThrow();
return(Spec.Expr(func1.And(func2)));
}
public void GetTickets_gets_query_provider_from_factory(IGetsTicketSpecification specProvider,
ISpecificationExpression <Ticket> spec,
IGetsQueryForTickets queryProvider,
TicketListRequest request)
{
// Arrange
var queryProviderFactoryUsed = false;
var specFactory = GetSpecFactory(s => specProvider);
var queryProviderFactory = GetQueryProviderFactory(s => {
if (s != spec)
{
return(null);
}
queryProviderFactoryUsed = true;
return(queryProvider);
});
Mock.Get(specProvider).Setup(x => x.GetSpecification()).Returns(spec);
Mock.Get(queryProvider).Setup(x => x.GetQuery()).Returns(() => null);
var sut = new TicketLister(queryProviderFactory, specFactory);
// Act
sut.GetTickets(request);
// Assert
Assert.That(queryProviderFactoryUsed, Is.True);
}
/// <summary>
/// Gets a new specification function which corresponds to the logical
/// combination of the specified objects: <c>AND</c>.
/// </summary>
/// <returns>A specification function.</returns>
/// <param name="spec">A specification expression.</param>
/// <param name="composeWith">A specification function.</param>
/// <typeparam name="T">The generic type of the specifications.</typeparam>
public static ISpecificationFunction <T> And <T>(this ISpecificationExpression <T> spec, ISpecificationFunction <T> composeWith)
{
var func1 = spec.GetFunction();
var func2 = composeWith.GetFunction();
return(Spec.Func <T>(o => func1(o) && func2(o)));
}
public virtual bool CheckExists(ISpecificationExpression <TEntity> specification)
{
CheckExists_Before(specification);
var result = Component.CheckExists(specification);
CheckExists_After(specification, result);
return(result);
}
/// <summary>
/// Filters a Linq queryable object using the predicate defined in a specification expression.
/// </summary>
/// <returns>A queryable object which is filtered by the specification predicate.</returns>
/// <param name="collection">A Linq queryable object.</param>
/// <param name="specification">A specification expression.</param>
/// <typeparam name="T">The generic type of the collection and the specification.</typeparam>
public static IEnumerable <T> Where <T>(this IEnumerable <T> collection, ISpecificationExpression <T> specification)
{
if (collection == null)
{
throw new ArgumentNullException(nameof(collection));
}
return(collection.Where(specification.GetFunction()));
}
public virtual IList <TEntity> GetList(ISpecificationExpression <TEntity> specification, int offset, int count)
{
GetList_Before(specification, offset, count);
var result = Component.GetList(specification, offset, count);
GetList_After(specification, offset, count, result);
return(result);
}
public override void Visit(Criterion node)
{
var spec = criterionConverter.ConvertToSpecification(node);
if (spec == null)
{
return;
}
specBeingBuilt = AddSpecification(spec, (node?.LogicalOperator) ?? default(LogicalOperator));
}
public Expression <Func <Ticket, bool> > GetExpression()
{
ISpecificationExpression <Ticket> output = Spec.Expr <Ticket>(x => true);
foreach (var labelName in labelNames)
{
var nameExpression = Spec.Expr <Ticket>(x => x.Labels.Any(l => l.Name == labelName));
output = output.And(nameExpression);
}
return(output.GetExpression());
}
/// <summary>
/// Filters a Linq queryable object using the predicate defined in a specification expression.
/// </summary>
/// <returns>A queryable object which is filtered by the specification predicate.</returns>
/// <param name="query">A Linq queryable object.</param>
/// <param name="specification">A specification expression.</param>
/// <typeparam name="T">The generic type of the query and the specification.</typeparam>
public static IQueryable <T> Where <T>(this IQueryable <T> query, ISpecificationExpression <T> specification)
{
if (query == null)
{
throw new ArgumentNullException(nameof(query));
}
if (specification == null)
{
throw new ArgumentNullException(nameof(specification));
}
return(query.Where(specification.GetExpression()));
}
public SpecificationQueryProviderDecorator(IGetsQueryForTickets decoratedInstance,
ISpecificationExpression <Ticket> specification)
{
if (specification == null)
{
throw new ArgumentNullException(nameof(specification));
}
if (decoratedInstance == null)
{
throw new ArgumentNullException(nameof(decoratedInstance));
}
this.decoratedInstance = decoratedInstance;
this.specification = specification;
}
internal static Expression <Func <T, bool> > GetExpressionOrThrow <T>(this ISpecificationExpression <T> spec)
{
if (spec == null)
{
throw new ArgumentNullException(nameof(spec));
}
var expr = spec.GetExpression();
if (expr == null)
{
throw new ArgumentException($"{nameof(ISpecificationExpression<T>)}<T>.{nameof(ISpecificationExpression<T>.GetExpression)}() must not return null.", nameof(spec));
}
return(expr);
}
// If this method needs to become any more complex, then break it away to a service of its own which gets
// a spec from a request.
ISpecificationExpression <Sprint> GetSpecification(ListSprintsRequest request)
{
var project = GetProject(request);
ISpecificationExpression <Sprint> spec = projectSprintFactory(project);
if (!request.ShowOpenSprints)
{
spec = spec.And(closedSprintFactory());
}
if (!request.ShowClosedSprints)
{
spec = spec.And(openSprintFactory());
}
return(spec);
}
public override void Visit(CriteriaGroup node)
{
if (node?.Criteria == null || !node.Criteria.Any())
{
return;
}
var recursiveVisitor = recursiveVisitorFactory();
recursiveVisitor.VisitLogicalCriteriaProvider(node);
var spec = recursiveVisitor.GetSpecification();
if (spec == null)
{
return;
}
specBeingBuilt = AddSpecification(spec, node.LogicalOperator);
}
public void ConvertToSpecification_uses_a_viable_strategy(Criterion criterion,
[MockedMetadata] IStrategyForConvertingCriterionToSpecification one,
[MockedMetadata] IStrategyForConvertingCriterionToSpecification two,
[MockedMetadata] IStrategyForConvertingCriterionToSpecification three,
ISpecificationExpression <Ticket> spec)
{
// Arrange
var strategies = new [] { one, two, three };
var sut = new StrategyBasedCriterionToSpecificationConverter(strategies);
Mock.Get(two.GetMetadata()).Setup(x => x.CanConvert(criterion)).Returns(true);
Mock.Get(two).Setup(x => x.ConvertToSpecification(criterion)).Returns(spec);
// Act
var result = sut.ConvertToSpecification(criterion);
// Assert
Assert.That(result, Is.SameAs(spec));
}
ISpecificationExpression <Ticket> AddSpecification(ISpecificationExpression <Ticket> toAdd,
LogicalOperator logicalOperator)
{
if (specBeingBuilt == null)
{
return(toAdd);
}
logicalOperator.RequireDefinedValue(nameof(logicalOperator));
switch (logicalOperator)
{
case LogicalOperator.Or:
return(specBeingBuilt.Or(toAdd));
case LogicalOperator.And:
return(specBeingBuilt.And(toAdd));
default:
throw new NotSupportedException($"The {nameof(LogicalOperator)} must have a supported value.");
}
}
ISpecificationExpression <Ticket> GetSpecFromFunction(PredicateFunction function)
{
ISpecificationExpression <Ticket> spec = null;
if (function.FunctionName == PredicateName.Function.IsEmpty)
{
spec = new HasNoStoryPoints();
}
if (function.FunctionName == PredicateName.Function.IsAnyOf)
{
spec = new StoryPointsIsOneOf(valueResolver.ResolveAll <int>(function.Parameters));
}
if (spec != null && function.Inverted)
{
spec = spec.Not();
}
return(spec);
}
public virtual void GetList_Before(ISpecificationExpression <TEntity> specification, int offset, int count)
{
}
/// <summary> /// Gets a single object from the query which matches the specification, or a default object if no instance was /// matched. /// </summary> /// <returns>The matched object or a default instance.</returns> /// <param name="query">A Linq queryable object.</param> /// <param name="specification">A specification expression.</param> /// <typeparam name="T">The generic type of the query and the specification.</typeparam> public static T SingleOrDefault <T>(this IQueryable <T> query, ISpecificationExpression <T> specification) => query.Where(specification).SingleOrDefault();
public virtual void GetList_After(ISpecificationExpression <TEntity> specification, int offset, int count, IList <TEntity> result)
{
}
public virtual void CheckExists_Before(ISpecificationExpression <TEntity> specification)
{
}
/// <summary> /// Gets the first object from the query which matches the specification. /// </summary> /// <returns>The matched object.</returns> /// <param name="query">A Linq queryable object.</param> /// <param name="specification">A specification expression.</param> /// <typeparam name="T">The generic type of the query and the specification.</typeparam> public static T First <T>(this IQueryable <T> query, ISpecificationExpression <T> specification) => query.Where(specification).First();
/// <summary> /// Gets a value which indicates whether or not any objects in the query match the given specification. /// </summary> /// <returns><c>true</c> if there are any matches for the specification; <c>false</c> otherwise.</returns> /// <param name="query">A Linq queryable object.</param> /// <param name="specification">A specification expression.</param> /// <typeparam name="T">The generic type of the query and the specification.</typeparam> public static bool Any <T>(this IQueryable <T> query, ISpecificationExpression <T> specification) => query.Where(specification).Any();
/// <summary> /// Gets a count of the objects within the query which match the specification. /// </summary> /// <returns>The count of matching objects.</returns> /// <param name="query">A Linq queryable object.</param> /// <param name="specification">A specification expression.</param> /// <typeparam name="T">The generic type of the query and the specification.</typeparam> public static int Count <T>(this IQueryable <T> query, ISpecificationExpression <T> specification) => query.Where(specification).Count();
/// <summary>
/// Gets a specification function which copies the specified specification expression.
/// </summary>
/// <returns>A specification function.</returns>
/// <param name="spec">A specification expression.</param>
/// <typeparam name="T">The generic type of the specification.</typeparam>
public static ISpecificationFunction <T> AsSpecificationFunction <T>(this ISpecificationExpression <T> spec)
{
return(Spec.Func(spec.GetFunction()));
}
public virtual void CheckExists_After(ISpecificationExpression <TEntity> specification, bool result)
{
}
/// <summary>
/// Gets a function from a specification expression, as if it were a
/// <see cref="ISpecificationFunction{T}"/>.
/// </summary>
/// <returns>A function, representing the compiled expression contained within the specification expression.</returns>
/// <param name="spec">A specification expression.</param>
/// <typeparam name="T">The generic type of the specification.</typeparam>
public static Func <T, bool> GetFunction <T>(this ISpecificationExpression <T> spec)
{
var expr = spec.GetExpressionOrThrow();
return(expr.Compile());
}
/// <summary>
/// Gets a new specification expression which corresponds to the logical
/// negation of the specified object: <c>NOT</c>.
/// </summary>
/// <returns>A specification expression.</returns>
/// <param name="spec">A specification expression.</param>
/// <typeparam name="T">The generic type of the specification.</typeparam>
public static ISpecificationExpression <T> Not <T>(this ISpecificationExpression <T> spec)
{
return(Spec.Expr(spec.GetExpressionOrThrow().Not()));
}
/// <summary>
/// Gets a <c>System.Predicate<T></c> from a specification expression.
/// </summary>
/// <returns>A predicate instance matching the specification.</returns>
/// <param name="spec">A specification expression.</param>
/// <typeparam name="T">The generic type of the specification.</typeparam>
public static Predicate <T> AsPredicate <T>(this ISpecificationExpression <T> spec)
{
var func = spec.GetFunction();
return(o => func(o));
}
/// <summary>
/// Gets a value which indicates whether a specified value matches/satisfies the specification.
/// </summary>
/// <returns><c>true</c> if the value matches the specification; <c>false</c> otherwise.</returns>
/// <param name="spec">A specification expression.</param>
/// <param name="value">The value to test with the specification.</param>
/// <typeparam name="T">The generic type of the specification and the specific type of the value object.</typeparam>
public static bool Matches <T>(this ISpecificationExpression <T> spec, T value)
{
var func = spec.GetFunction();
return(func(value));
}
/// <summary>
/// Transforms a specification object to a new specified-type, by using a selector expression to indicate how
/// the intended type will provide the originally-specified type.
/// </summary>
/// <returns>A transformed specification object.</returns>
/// <param name="spec">The original specification to transform.</param>
/// <param name="transformation">A transformation to perform on the specification.</param>
/// <typeparam name="TOrigin">The original specified type.</typeparam>
/// <typeparam name="TTarget">The new specified type (after transformation).</typeparam>
public static ISpecificationExpression <TTarget> Transform <TOrigin, TTarget>(this ISpecificationExpression <TOrigin> spec,
Func <IGetsTransformedSpecificationExpression <TOrigin>, ISpecificationExpression <TTarget> > transformation)
{
if (spec == null)
{
throw new ArgumentNullException(nameof(spec));
}
if (transformation == null)
{
throw new ArgumentNullException(nameof(transformation));
}
var transformer = new SpecificationExpressionTransformer <TOrigin>(spec);
return(transformation(transformer));
}
